An AED (Automated External Defibrillator) is a portable electronic device that analyzes the rhythm of the heart and delivers an electrical shock, known as defibrillation, which helps the heart re-establish an effective rhythm.

Warning: When using an AED, there are a couple of important things to keep in mind as it relates to your surroundings.

  • Are there combustible gases or liquids at the scene?
  • Are there any liquids that could connect the victim with yourself, the responder, or someone else, that could result in electrocution?

Pro Tip #1: If the scene isn't safe enough to use an AED, drag or move the patient to a safer area where you won't have to worry about explosives or electrocution from any water first, then use the AED.

These are two important considerations before using an AED, but there are a few other things to note when defibrillating an adult patient.

  • If the victim is female and wearing an underwire bra, it shouldn't present any complications. However, if it is a concern, you can disconnect it and remove it from the pathway to the heart.
  • Necklaces should be moved to the side
  • Any patches – nicotine, analgesic, nitro gel, etc. – should be removed if they are in the way of the pads
  • Piercings shouldn't cause any problems
  • It's OK if the victim or the victim's clothing is wet, as long as the chest area is dry and you or the victim aren't submerged in water or connected by it
  • There are no special considerations for pregnant women

Pro Tip #2: It's OK to be just as aggressive with a pregnant woman as you would any other patient. The primary focus should be on the mother, as saving her will also help save the baby. The care you provide to the mother won't put the baby in any more jeopardy.

How to Provide Care

As always, the first thing you want to do is make sure the scene is safe and that your gloves are on. Make sure you have your rescue mask with a one-way valve handy and begin calling out to the victim to assess whether or not he or she is responsive.

Are you OK? Can you hear me?

If you don't get an initial response, place your hand on the victim's forehead and tap on his or her collarbone. If you still do not get a response, proceed with the following steps.

  • Call 911 and activate EMS or call in a code if you're in a healthcare setting. If there is a bystander nearby, you can ask for their help – calling 911, locating an AED, etc. In the event that you do not know how to proceed, call 911 on your cell phone, put it on speaker, and follow their instructions.
  • Continue to assess the victim's responsiveness and vital signs – signs of breathing normally, signs of a pulse, etc.
  • Check for the carotid pulse, located between the trachea and sternocleidomastoid muscle, in the valley between these two structures. Use the flat parts of your index and middle fingers and press with moderate force in that valley. Spend no more than 10 seconds looking for a pulse.
  • If you've determined at this point that the victim is unresponsive, not breathing normally, and has no pulse, continue immediately with your AED.

AED Technique for Adults

  • Turn on the AED.
  • Remove the patient's clothing to reveal a bare chest and dry the chest off if it's wet.
  • Attach the AED pads to the patient's chest. The pads should have a diagram on placement if you need a reminder. The first pad goes on the top right side of the chest. The second pad goes on the bottom left side mid axillary, under the left breast. Make sure they adhere well.
  • Plug the cable into the AED and be sure no one is touching the patient, including yourself. The AED should now be charging and analyzing the rhythm of the patient's heart.
  • If the scene is clear and no one is touching the patient, push the flashing shock button. Then go right into CPR. It's OK to perform CPR over the pads, so don't worry about moving them.
  • Stand or kneel directly over the patient's chest. Lock your elbows and use only your upper body weight to supply the force for the chest compressions, and count as you perform them.
  • Conduct compressions that go 2-2.4 inches deep (or 1/3 the depth of the victim's chest) and at a rate of between 100 and 120 compressions per minute, which amounts to two compressions per second.
  • Perform 30 chest compressions.
  • Grab the rescue mask and seal it over the victim's face and nose.
  • Lift the victim's chin and tilt his or her head back.
  • Breathe into the rescue mask and wait for the chest to rise and fall before administering the next breath.
  • After one round of CPR, let the AED analyze the patient again. If the AED advises you to perform another shock, make sure no one is touching the patient and press the shock button.
  • Go right back into CPR.

Continue this cycle of CPR, re-analyzation, charging, shock, back into CPR until help arrives, the patient is responsive and breathing normally, or the next level of care takes over.

A Word About Abnormal Heart Rhythms

The most common abnormal heart rhythm that causes cardiac arrest is known as ventricular fibrillation, or V-fib, for short. When in V-fib, the patient's heart ventricles fibrillate, or quiver, without any organized rhythm. Electrical impulses fire randomly, which prevents the heart from pumping and circulating blood.

Another less common and less life-threatening abnormal heart rhythm is called ventricular tachycardia, or V-tach, for short. In V-tach, the heart is controlled by an abnormal electrical impulse that fires too fast for the heart's chambers to completely fill, which disrupts the heart's ability to pump and circulate blood.

Both V-fib and V-tach typically result in no pulse and no normal breathing.